#include <iostream>
#include <jsoncpp/json/json.h>

int main(){
  std::string str = "进程间通信";
  std::string ret = str.substr(0, 1);
  std::cout << ret << std::endl;
  return 0;
}
  //std::string str = "01234";
  //size_t end = str.size() - 1;
  //std::string ret = str.substr(0, end);
  //std::cout << ret << std::endl;
